She recommends reserving pH impedance testing until after testing for other upper airway inflammatory causes. “Your initial evaluation is gong to dictate that next step,” she said.
Joel Blumin, MD, chief of the division of laryngology and professional voice at the Medical College of Wisconsin in Madison, said patient preference has to be factored into the extent of testing and treatment. For example, some patients may come in only to rule out cancer, and their evaluation should be tailored with that in mind.
Peter Doble, MD, an otolaryngologist at Sawtooth Surgery Center in Twin Falls, Idaho, said he is not quick to order pH impedance testing, largely due to the rural demographics and cost-conscious nature of his patients. “I reserve testing for people who aren’t responding to any treatment modality,” he said. “I find testing to be an inadequate tool for me. … If the argument were, ‘This test is successful in making a diagnosis 85% of the time,’ then maybe we’d sell that. But if there’s more of an ‘if’ factor than that—and I think there is—it’s a very difficult sale.”
If pH impedance testing is reserved for those refractory to treatment, how is that measured? Dr. Dailey wondered. “I’m pretty sure we don’t have either a cut-off, or certainly not a uniform cut-off, as a field to be able to determine what constitutes failure,” he said. “So it seems like there’s a lot of variability, probably, if I had to guess, in terms of when to apply so-called ‘advanced testing’ and when not to.”
Interpretation
Dr. Blumin said that when performing impedance testing, symptom association to reflux events is not always easy to interpret. There are subtleties involved when trying to correlate a reflux event with a given symptom such as cough. When they do coincide, he said, “It’s nice when it happens.”
Dr. Doble said that a patient with long-time cough who takes a PPI every day might be difficult to assess. “I might stop PPIs for 30 to 45 days to see if symptoms change or worsen,” he said. If the symptoms are unchanged, he would look into other causes.
Dr. Garrett said that when considering a Nissen procedure to try to surgically correct reflux, it’s important to remember that it is generally more effective in patients who have been better responders to acid-suppression therapy and have some true GERD-type symptoms, such as heartburn.
Panelists generally agreed that pH impedance testing is a good idea after surgical procedures for reflux to quantify how well patients respond. An audience member even said that post-op findings from this test led one of the surgeons at his center to refine the technique.